Stability of DMPC Liposomes Externally Conjugated with Branched Polyglycerol
Vesicles formed by DMPC liposomes externally conjugated with branched polyglycerol-dendrons as well as linear PEG in water solution were simulated using the DPD method. Such a structure of vesicles corresponds to the structure of polymer-grafted liposomes obtained experimentally by the post-insertio...
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MDPI AG
2022-08-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/23/16/9142 |
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| author | Alexander A. Beketov Ivan V. Mikhailov Anatoly A. Darinskii |
| author_facet | Alexander A. Beketov Ivan V. Mikhailov Anatoly A. Darinskii |
| author_sort | Alexander A. Beketov |
| collection | DOAJ |
| description | Vesicles formed by DMPC liposomes externally conjugated with branched polyglycerol-dendrons as well as linear PEG in water solution were simulated using the DPD method. Such a structure of vesicles corresponds to the structure of polymer-grafted liposomes obtained experimentally by the post-insertion method, in which polymer chains are fixed on the outer surface of the liposome. The grafting density, generation number and spacer length of grafted dendrons were varied. It was shown that modification of the outer surface of liposomes due to grafting of hydrophilic dendrons has practically no effect on the size and shape of the vesicle, as well as on the morphology of the lipid membrane up to certain critical thresholds of grafting density, degree of polymerization, and generation number of grafted molecules. Exceeding the threshold values of these structural parameters leads to irreversible deformation of the lipid membrane. Diffusion through the membrane and the transition of grafted molecules from the outer surface of the liposome to the inner surface is not observed for dendrons with a generation number higher than one, even at high grafting densities. The critical values of the generation number and the characteristics of the molecular coating at these values were determined for various grafting densities and spacer lengths of the grafted chains. It was shown that the chemical potential of the grafted dendron can serve as a stability metric for the conjugated liposome. The chemical potential of grafted molecules was calculated using the mean field model of the spherical brush on the liposome surface. An analysis of the simulation data shows that, within the framework of the applicability of the mean field approach, the value of the chemical potential is a sufficient criterion for separating vesicles into stable and unstable forms. These results can be used as a guide for the experimental design of nanocontainers based on lipid vesicles with an external protective coating of branched macromolecules. |
| first_indexed | 2024-03-09T09:55:52Z |
| format | Article |
| id | doaj.art-f04cac0437d14e6e9fc1f544392a8431 |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-09T09:55:52Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-f04cac0437d14e6e9fc1f544392a84312023-12-01T23:47:37ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672022-08-012316914210.3390/ijms23169142Stability of DMPC Liposomes Externally Conjugated with Branched PolyglycerolAlexander A. Beketov0Ivan V. Mikhailov1Anatoly A. Darinskii2Center for Chemical Engineering, St. Petersburg National Research University of Information Technologies, Mechanics and Optics, 197101 St. Petersburg, RussiaInstitute of Macromolecular Compounds, Russian Academy of Sciences, 199004 St. Petersburg, RussiaInstitute of Macromolecular Compounds, Russian Academy of Sciences, 199004 St. Petersburg, RussiaVesicles formed by DMPC liposomes externally conjugated with branched polyglycerol-dendrons as well as linear PEG in water solution were simulated using the DPD method. Such a structure of vesicles corresponds to the structure of polymer-grafted liposomes obtained experimentally by the post-insertion method, in which polymer chains are fixed on the outer surface of the liposome. The grafting density, generation number and spacer length of grafted dendrons were varied. It was shown that modification of the outer surface of liposomes due to grafting of hydrophilic dendrons has practically no effect on the size and shape of the vesicle, as well as on the morphology of the lipid membrane up to certain critical thresholds of grafting density, degree of polymerization, and generation number of grafted molecules. Exceeding the threshold values of these structural parameters leads to irreversible deformation of the lipid membrane. Diffusion through the membrane and the transition of grafted molecules from the outer surface of the liposome to the inner surface is not observed for dendrons with a generation number higher than one, even at high grafting densities. The critical values of the generation number and the characteristics of the molecular coating at these values were determined for various grafting densities and spacer lengths of the grafted chains. It was shown that the chemical potential of the grafted dendron can serve as a stability metric for the conjugated liposome. The chemical potential of grafted molecules was calculated using the mean field model of the spherical brush on the liposome surface. An analysis of the simulation data shows that, within the framework of the applicability of the mean field approach, the value of the chemical potential is a sufficient criterion for separating vesicles into stable and unstable forms. These results can be used as a guide for the experimental design of nanocontainers based on lipid vesicles with an external protective coating of branched macromolecules.https://www.mdpi.com/1422-0067/23/16/9142liposomesDPD simulationsstabilitybranched polyglycerol |
| spellingShingle | Alexander A. Beketov Ivan V. Mikhailov Anatoly A. Darinskii Stability of DMPC Liposomes Externally Conjugated with Branched Polyglycerol International Journal of Molecular Sciences liposomes DPD simulations stability branched polyglycerol |
| title | Stability of DMPC Liposomes Externally Conjugated with Branched Polyglycerol |
| title_full | Stability of DMPC Liposomes Externally Conjugated with Branched Polyglycerol |
| title_fullStr | Stability of DMPC Liposomes Externally Conjugated with Branched Polyglycerol |
| title_full_unstemmed | Stability of DMPC Liposomes Externally Conjugated with Branched Polyglycerol |
| title_short | Stability of DMPC Liposomes Externally Conjugated with Branched Polyglycerol |
| title_sort | stability of dmpc liposomes externally conjugated with branched polyglycerol |
| topic | liposomes DPD simulations stability branched polyglycerol |
| url | https://www.mdpi.com/1422-0067/23/16/9142 |
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